Five years after the World Health Organization declared Covid-199 Pandemic, and hundreds of millions of cases, scientists have a clear picture of how the virus can affect the body for a long time after the infection has passed.
Immediately after the virus began to spread, some of the effects of Cobid became clear. We quickly understood how deadly the infection could be for people with fundamental conditions such as diabetes and heart disease. However, many years of research was needed to understand how the cobid match could lead to changes in other parts of the body and sometimes invisible.
Some of these effects, such as chronic fatigue and brain fog, are considered long covid and defined as symptoms of infections that last for more than three months. Some estimates show that 400 million people around the world have been diagnosed with long -term long -term cobids. However, infections can also lead to other problems, including lung and heart damage and microbial changes in the intestines, which are not always recognized as long covid, but still can still have health.
We now better understand what is behind these changes, including the role of extensive inflammation that can occur covid. If the virus disappears in most people, the inflammation will sink. However, Dr. Braden Kuo, a neuroscientist at the Massachusetts General Hospital, said, “For some people, it can last as a” slow burn “with a slow burn.
Here’s what scientists have learned about inflammation and other factors that cause this impact.
lung
Covid can stimulate the lungs and cause long -term problems such as continuous breathing and cough. In rare cases, covid can cause pneumonia for the patient to leave scars and small tissues throughout the lungs. The scar can be more difficult to breathe. small research More than 10 % of those who are admitted to cobid infections have suggested that there is a problem different from the lung scar two years later.
cause : The virus invades Cell along the prayerIt can cause inflammation and sometimes attack and destroy healthy lung tissues. Dr. Ziyad Al-ALY, chief clinical epidemiologist of Washington University in St. Lewis, said that this can damage the ability to convey the oxygen of the lungs throughout the body.
When the lungs are restoring and repairing, they form scars. However, the scar tissue itself can stiffen the lungs and reduce the lung dose, which can lead to persistent symptoms such as coughing and shortness of breath.
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Kobid can cause short -term symptoms such as nausea, vomiting and diarrhea.
But for some people, covid can cause chronic camouflage problems such as reflux, constipation, diarrhea and abdominal pain. This problem can last for months or years. A 2024 StudyResearchers estimated that the match with Kovid left 13 %of the 10 %of people who continued to pain and 13 %after a year of gastrointestinal problems.
cause : Scientists don’t know exactly why Covid can throw too much normal intestinal function, but he understands more of what they can do. For example, it is clear now The virus can interfere with the intestinal microbial cluster.Reduces beneficial microorganisms and increases the number of harmful microorganisms. “Good” microorganisms can help you step on inflammation, but “bad” microorganisms can increase “bad” microorganisms.
Inflammation from the infection itself and the changed intestinal microorganisms can harm the lining of the intestine. This allows toxins and damaged components to escape from the intestines to other tissues in the body. Immune cells then cause a certain food to allergen, which can cause food intolerance.
Dr. Kuo said inflammation can be “chew” in the nerves that control the intestinal contraction of intestinal pain or continue to move food. This can cause stomach or intestinal pain or move too quickly or too slow through the digestive tract, which can cause symptoms such as diarrhea or constipation.
brain
At the height of the infection, patients often cause headaches, dizzy and confusing. They sometimes find out that there are difficulties in finding or focusing on the right words, having difficulties in conversations, or different memories.
These symptoms can remain. Studies have been found roughly 20 to 30 % People infected with covid experienced brain fog at least three months after the initial infection. Studies have shown that Covid can lead to anxiety or depression or worsen existing mental health problems.
cause : Scientists are still trying to identify all the elements that contribute to continuous neurological issues after Kobid. But a culprit looks clear: persistent inflammation that damages neurons and produces major connections between synapses. All of this can cause the same symptoms as described above. Some researchers also help to explain why infections can cause or worsen mental health problems because they think that cognitive and emotions are especially vulnerable to inflammation.
Another theory is that the virus interferes. Blood brain barrier, It is essential for protecting brain tissue and cognitive function.
The sculptures of the virus can also remain in the brain for a long time, which can be explained why some of the symptoms persist beyond early infections.
mind
Covid-19 infection increases the risk of heart problems, including irregular heartbeats known for heart attack, stroke, heart muscle damage and arrhythmia. One big study shows that Kobid has doubled the risk of major cardiovascular events for up to three years.
cause : If you have acute cobid infections, the stress of heat and inflammation can give excessive demand to your heart. For those who already have plaque accumulation in arteries or heart muscles that have begun to become stiff, the demand can lead to irregular heartbeat or heart attack.
But scientists think that more common is that the virus causes inflammation that damages the heart muscles. Viruses can also cause inflammation by damaging cells surrounding blood vessels. This allows new coagulation to form an existing plaque or block blood vessels. This type of blockage can suddenly die from a heart attack or cause downstream damage to the heart muscles and other tissues, causing heart failure or arrhythmia.
Those who are hospitalized in COVID have the highest risk of short -term and long -term risk of heart complications. Some studies have shown that people with O non -blood types (A, B or AB) may especially risk because the blood type may be associated with blood clotting methods.
Circulatory system
A study of long covid patients shows that the body is difficult to transfer blood from the legs and abdomen and return to the heart. It can reduce the amount of blood pumped by the heart, which may be bad after fatigue, shortness of breath and exercise.
cause : It is not clear why this circulation problem occurs, but scientists harm inflammation in certain nerve fibers outside the spinal cord, which controls the pressure of the brain. Dr. David Systrom, a lung and intensive careist at Boston’s Brigham and Women’s Hospital, said blood flow could be damaged.
Dr. Systrom said in some patients with long covids that muscles cannot extract oxygen from the blood rather than normal, preventing the ability to catch up with exercise. In addition, mitochondria, the energy -producing power of cells, do not work properly or at maximum doses, which can reduce the popularity of muscle tissue.
